Critical Mass Intergalactic 20th (and 10th) Anniversary Critical Mass began in September, 1992. Here are some ph...

⚇ At last, the full flickr set of my Intergalactic #CriticalMass 20th Anniversary photos: http://flic.kr/s/aHsjCm4R1Z #CMXX #sfcm20

sep2012 cmxx-velorution-paris · Some vélorutionaries from Paris, bearing a sign with a ...

⚇ Parisian vélorutionaries (not pirates) at the 20th Anniversary of #CriticalMass: http://flic.kr/p/dh7tFY #arrr #BikeSF #CMXX #sfcm20

sep2012 cmxx-pedicab-at-start · Here's the whole pedicab at the start of the ride for L...

⚇ Baby in pedicab at the start of the 20th Anniversary #CriticalMass: http://flic.kr/p/dgqACW #BikeSF #CMXX #sfcm20

sep2012 cmxx-allie-virginia-pedicab · At 5 months old, Virginia is too young for a bike carri...

⚇ Five months old at the 20th Anniversary Critical Mass ride. #BikeSF #CriticalMass #sfcm20 http://flic.kr/p/dfPhkP

RT "@sfyellowbike: What an amazing, breathtaking, life changing and socially powerful @sfcriticalmass #SFCM20 #beapart <3 dingding" #BikeSF

RT "@SFBikeParty: Sorry chevron. We ride bicis. #SFCM20 #SFBP http://t.co/HA8ViEXa" #BikeSF

RT "@allysoneb: #sfcm20 was the first time I fully felt safe riding a bike on SF streets. #CriticalMass #bike" #BikeSF